Incentives question

No you shouldn't bother.

Dump nanab berries for stardust and you have a chance of getting a candy of that Pokémon. There's incentive to keep the gym up for ur team but have 1-2 weak defenders and hope they get kicked out so there's an open spot.

Mainly for now, the incentive is you get stardust for each berry you feed a pokemon and you get extra items because you're team controls that gym.
And as an extra incentive, if your bag is full at that time you can dump all those nanab berries to open up space but actually get something in return for them

Stardust, and you help keep the gym on your team.

I intend to feed allied mons when I can, but only mons that I think belong in the gym, ie, garbage pokemon that don't make the gym harder to take don't get fed, in the hopes that they get knocked out faster, so better mons can be placed.

I will feed Nanab berries to Dragonite, Lax, Blissey, T-Rex and Lapras. Porygon and Muk as well. Chance of candy + stardust is a pretty good incentive. Other Pokemon I won't bother with.

Hmmm.. wonder if I could get regional pokemon candy without having the pokemon? I fought a Mr. Mime today...